1. Field of the Invention
This invention relates to a scanner, especially to a built-in scanner for computers.
2. Description of Related Art
A built-in scanner is a compact scanner built inside a computer. There are many advantages for a computer with a built-in scanner such as: it is compact and easily portable. Since more and more computer users buy scanners as common accouterment, built-in scanners are greatly required. The built-in scanner of the prior art has a document tray whose function likes the CD-ROM player's tray of a computer. The work cycle of the built-in scanner of the prior art is described as follows. When users want to scan a document sheet, the document tray is pulled out for users to put a document sheet. Then, the document tray with the document sheet is moved inward for scanning. As the document sheet is completely scanned, the document tray is pulled out again for users to take the scanned document sheet out.
A major problem of the prior art is that since the document tray with the document sheet is moved forward and backward when the document sheet is scanned, the motion vibration degrades the scan quality.
Another problem of the prior art is that only one document sheet can be scanned in one work cycle.